1. Field of the Invention
The present invention relates to burn-in systems for burning in integrated circuits, hybrid modules and other electronic devices in general and in particular to a programmable low profile universally selectable burn-in board assembly for use in such systems.
2. Description of the Related Art
Typical burn-in board assemblies are constructed using two-sided or multilayer printed circuit burn-in mother boards to distribute DC voltages and circuit drive signals (data patterns) from input edge fingers to each socket on the burn-in mother board. The sockets and all peripheral components are soldered on the burn-in mother board using high temperature solder. Such burn-in mother boards are typically dedicated to a specific product and package type with the traces on the mother board comprising a fixed program for activating the components in the device mounted in the socket.
Other methods of programmability have been utilized in the past using dual row connectors and programmable printed circuit cards (program cards) which are positioned in a plane at a 90.degree. angle from the plane of the burn-in mother board.
Still other methods of programmability have included arrangements wherein the connector and program card are installed in a parallel plane with the burn-in mother board to reduce the vertical height of the burn-in mother board and program card combination.
Both of the above-described methods tend to reduce the number of socket positions on a burn-in mother board. Moreover, the method in which the plane of the program card is 90.degree. to the plane of the burn-in mother board also, in most cases, takes up two burn-in board positions in the burn-in system because of typical spacing between burn-in mother board positions in the system.
As will be noted, both of the above-described methods for creating a programmable burn-in mother board versus a dedicated burn-in mother board reduce the socket density on the burn-in mother board. Furthermore, the latter method in which the plane of the program card is 90.degree. to the plane of the mother board also decreases the board density of the burn-in system by fifty percent (50%), thereby requiring a user to purchase twice as many burn-in systems for the same number of burn-in mother boards.